Internal combustion engine



March 28, 1933.

D. F. AsE'xURY INTERNAL COMBUSTION ENGINE Filed Nov. 2o, 1931 Patented Mar. 28, 1933 UNITED STATES PATENT OFFICE DOBSEY F. ASBURY, OF BROOMES ISLAND, MARYLAND INTERNAL COMBSTION ENGINE Application led November 20, 1931. Serial No. 576,388.

My invention relates to internal combustion most to the outer end of the stem 13 and is engines and has for its objects to provide a ported laterally at a point close to the outer shield inside the combustion chamber of the faceof the casting A, as at 15, for the purpose ,e engine which obstructs the nearest straight of relieving the outer half of the stem bear- 5 and therefore highest velocity path of eX- ing from exhaust pressure, so that said half "55 haust products discharging from the combusof the bearing may be maintained properly tion chamber, so that any two opposite sides lubricated while the engine is running. A of the stem of the valve controlling the discoil valve spring 16 surrounds the outer half charge of exhaust products from the combusof the bearing 14 and reacts from the' outer 1 tion chamber will be heated to substantially face of the casting A against the valve stem 60 the same temperature and expand the same 13 to normally maintain the valve head 12 enamount, so that the valves head is caused to gaged upon its seat 12 The outer or movseat central and level at all times; to reduce able end of the spring 16 is engaged in a pockthe amount of heat imparted to the valves et formed in the valve stem in the manner de- R 15 head during exhaust; to cause the valves Serbed and Claimed in my prior Patent '65 head to seat level and thereby give up heat 1,789,209, such engagement of the spring with uniformly all around its seat to the water the valve stem being effected through an opencooled casting of the engine; and to maintain ing 17 in the bearing and located some disthe valve Stem from Wel-ping and thus permit tance from the outer end thereof, so as to prothe use of a 20 valve seat, so that the diameter v ide a fixed bearing for the valve stem on both "7 of the valve port and the lift of the valve may SldeS Of the point Where it is engaged by the be decreased perceptbly and Still have more mOVableveIlCl Of the Spring WhCll reduCeS the opening affording communication between leverage of any transverse force delivered to the valve port and combustion chamber when the Stem by the spring or other valve operatr the valve is lifted after deducting the amount lng parts- This Construction of providingy 5 of the opening obstructed by the shield. fixed bearing for the valve stem on opposite In the drawing chosen to illustrated my in- SldeS Of the pOIlt Where the stem is engaged vention, the scope whereof is set forth in the byw movable @11d 0f the Valve Spring 1S n A appended Chime, claimed in my prior application Serial Num D 30 Figure 1 is a vertical section of a cylinder be? 528,941, lllefl API* 9 1931- The Valve B'so head casting showing my invention incorpo. 1s adapted to be lifted to open position against rated;l and the spring 16, as shown in Figure 1, by the Figure 2, a Section on the line 2 2 ef Figaction of the oscillating rocker arm 18 which ure 1 with a, fragment 0f the exhaust valve latter is journaled on a hollow bearing melnp head Shown in elevation, ber 19 supported by a standard 20 rising from 85 Referring to the drawing A indicates the the casting A. One end of the rocker arm 18 cylinder head casting of a water cooled inengages the outer end of the valve stem 13 ternal combustion engine, said casting being While the other end thereof is engaged by a shaped to provide the combustion chamber tappet rod 21 from which latter force is. 10 of an engine cylinder and to also provide transmitted to operate the rocker arm against an exhaust port 11 into end through which the influence of the spring 16 to lift the valve exhaust productsV are discharged from the B. The interior 0f the member 19 is adapted chamber 10. The mouth of the port 11 is oonto be connected with the oil system of the entrolled by an exhaust ,poppet valve B which gine and is provided with ports 22 and 22i includes a head 12 and stem 13, said stem bethrough the latter 0f Which Oil s Supplied t0 95 ing slidable in a bearing 14 mounted in the passages 23 and 24 in the rocker arm 18 casting A and having a portion between the through a groove 25 also in the rocker arm. bearing and valve head exposed to exhaust Oil supplied to the passage 24 is delivered to y products in the port 11. This bearing 14 is the upper end of the tappet 21, while oil deprolonged on the outside of the casting A allivered to the passage 23 is intermittently 100 thrown against the outer end of the valve stem 13 as the arm 18 rocks.

It will be noted that the port l1 extends away from the side a of the valve stern and 5 on the opposite side of the mouth of the port from said stem side a I provide a shield 26 located inside the combustion chamber. In the present instance I show the shield as an integral part of the casting A and formed with an arcuate surface 26 concentric with and spaced from the periphery of the valve head 12 and having its elements substan tially parallel to the direction of movement of the valve B, In the absence of the shield 26 the highest velocity path of exhaust products in passing from the combustion chamber into the port l1 would be along the dotted lines ca and as the rate of imparting heat to a surface by hot combustion products varies as the velocity of products by the surface and does not vary with the size of the opening through which the products of combustion travel and as the stem is located in the middle of such path of high velocity direct impingement of the exhaust products against the valve stem will occur with the result that the side of the valve stem would be heated to a higher temperature than the side L with a resulting greater amount of expansion on the side Z) than on the side a and warping of the stem and erroneous positioning of the valve head with respect to its seat. My shield 26 eliminates this straight path of high velocity and deflects the exhaust products in such manner that their velocity is equalized around the valve stem 13 and an even temperature maintained throughout said stem, so that the stem will expand straight longitudinally and maintain the valve head in proper relation to its seat. Furthermore, the shield 26 is effective to maintain the temperature of that portion of the valve head l2 opposed to the shield at the same temperature as the corresponding opposite portion of the head by controlling the velocity of products of combustion in their passage by the valve head within the extent of the shield. It will further be noted, in the functioning of the shield 26, that an eddy of exhaust products is maintained on the side Z) of the valve stem which products would, in the absence of the shield, impinge against the stem at their highest velocity. The presence of this eddy of exhaust products is due to the fact that the exhaust products entering the port between the valve head and shield and those products which enter the port at each side of the shield collide in the port with a resulting eddy and diminution in the velocity of the exhaust products before contact with the valve stem.

At extra high engine speed, when slow burning high test gasoline is used, the pressure of the left over products of combustion in the combustion chamber is higher than the pressure in the intake manifold when the intake valve starts to open. This diderence in pressure at that time causes the left over hot products of combustion to rush out into the intake manifold and impinge against only one side of the intake valve stem and heat that side, the opposite of the stem is cooled by the cold intake mixture impinging thereagainst during the intake stroke. This above double action of heating one side of the stem and cooling the opposite side is liable to warp the stem enough to prohibit the valve head from seating properly. The stem shield takes care of the heat imparted to the valve stem in the same manner as described in my prior application Serial Number 535,525, filed May 6, 1931. This precaution is taken beca-use the 2Oo angle of seat on the valve is not steep enough to provide a self-centering feature. The standard 45 angle of seat has the self centering feature and it needs it more than any other angle of seat possible for its conical surface is just about perpendicular to the direction of the shift of the position of the valve head due to a warp or incline of the valve stem.

In Figure 2 there is disclosed an intake port 27, intake valve stem 28, and an intake valve stem shield 29 in the port 28. This shield 29 forms the claimed subject matter of my prior application 535,525.

I claim:

1. In a gas engine structure, a cylinder including a gas port having entrance and discharge ends, a poppet valve controlling the entrance end of the port, said valve ineludin g a head and a stem with the latter having a length thereof exposed to gas current in the port, and means inside the combustion chamber shielding from the gas current only that side of the exposed length of the stem which is remote from the discharge end of the port.

2. In a gas engine structure, a cylinder including a gas port having entrance and discharge ends.r a poppet valve controlling the entrance end of the port, said valve including a head and a stem with the latter having a length thereof exposed to gas current in the port, and a formation on the cylinder inside the combustion chamber at the side of the port entrance end which is remote from the port discharge end shielding the side of the valve stem adjacent thereto from the gas current. F120 3. A structure for internal combustion engines comprising a poppet valve controlling the mouth of an exhaust port and having its stem exposed to exhaust products in the port, said port extending in a direction from one side of the valve stem, and a shield inside the combustion chamber of the engine located adjacent to the side of the mouth of the port which is remote from said side of the valve stem and spaced from the periphery 130 of the valve head, said shield being formed so that it is ine'ective to reduce the area of valve opening per lift until the lift of the valve is equal to the space between the valve 5 heads periphery and the shield. Y

In testimony whereof I hereunto aX my signature.

DORSEY F. ASBURY. 

